What exactly are you looking for? There is a number of docs directly on the orbworks site. And if you are looking for a basic intro into C programming using PocketC, I wrote such a tutorial a long time ago, I can email it to you. Contact me at sales(AT)pdamusician.com if you are interested.

As for GUI programming (i.e. pushbuttons, forms etc.) I highly recommend downloading the demo version of PCForms, the included docs, source files, and the code that PCForm generates are highly usable.